We usually listen to audiobooks while we're driving. We've gone through the whole Harry Potter series (after reading them in hard copy). We've also tried out some new authors. We didn't like Ursula LeGuin's first Earthsea book very much, but we did like Terry Goodkind's first Sword of Truth book (something I can't say about the new TV adaptation Legend of the Seeker, which doesn't have much of anything to do with the book besides the character names and a few very general characteristics taken from the original storyline but modified enough to remove the most interesting aspects). Sam has long been a fan of Anne McCaffrey's Pern series, and we listened to one of those also (after having read a bunch). I'm not as impressed with her writing, but I like the world she's created, which is one of the things I like about fantasy and science fiction in general.
One of the problems we keep running into is that we listen to something and then can't continue on because our library doesn't have an audio version of the next volume in the series. They don't have the second Goodkind book or the next McCaffrey one after Moreta, where we left off. We also are re-reading Terry Pratchett's Discworld series, and the library had book 6, so we've been listening to that, but they only have a few more, and they're much later in the series. We could always listen to books we've read or ones one of us has read. I'm thinking Lloyd Alexander might be good (new to Sam). There is always Tolkien or Lewis if we want to go through those again. Our library system has Stephen Lawhead's first few volumes in the Arthur/Pendragon series. I tried reading the first one when it came out but didn't get very far, and maybe having an audio version would make it easier to get through it.
But I'm wondering if anyone has further recommendations of authors to try who would be similar to what we've liked. I don't like Stephen Donaldson. I thought his white gold series was awful. Besides what I've mentioned, we both really like Terry Brooks. I've thought about Robert Jordan, Tad Williams, Raymond Feist, Fred Saberhagen, Katherine Kerr, and David Eddings, but their respective first volumes aren't in the library system. They do have some of the Dune series, including the first one, but I'm somewhat hesitant about that unless Sam decides to push it. Roger Zelazny's Nine Princes in Amber is available, but I don't know much about that other than seeing his name mentioned a lot in scifi/fantasy contexts.